window.cpp

/******************************************************************************** Copyright (C) 2009 Nokia Corporation and/or its subsidiary(-ies).** Contact: Qt Software Information (qt-info@nokia.com)**** This file is part of the documentation of the Qt Toolkit.**** $QT_BEGIN_LICENSE:LGPL$** Commercial Usage** Licensees holding valid Qt Commercial licenses may use this file in** accordance with the Qt Commercial License Agreement provided with the** Software or, alternatively, in accordance with the terms contained in** a written agreement between you and Nokia.**** GNU Lesser General Public License Usage** Alternatively, this file may be used under the terms of the GNU Lesser** General Public License version 2.1 as published by the Free Software** Foundation and appearing in the file LICENSE.LGPL included in the** packaging of this file. Please review the following information to** ensure the GNU Lesser General Public License version 2.1 requirements** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.**** In addition, as a special exception, Nokia gives you certain** additional rights. These rights are described in the Nokia Qt LGPL** Exception version 1.0, included in the file LGPL_EXCEPTION.txt in this** package.**** GNU General Public License Usage** Alternatively, this file may be used under the terms of the GNU** General Public License version 3.0 as published by the Free Software** Foundation and appearing in the file LICENSE.GPL included in the** packaging of this file. Please review the following information to** ensure the GNU General Public License version 3.0 requirements will be** met: http://www.gnu.org/copyleft/gpl.html.**** If you are unsure which license is appropriate for your use, please** contact the sales department at qt-sales@nokia.com.** $QT_END_LICENSE$******************************************************************************/#include <QtGui>#include <math.h>#include "window.h"Window::Window(QWidget *parent)
: QWidget(parent)
{
text = QString("Support for text rendering and layout in Qt 4 has been ""redesigned around a system that allows textual content to ""be represented in a more flexible way than was possible ""with Qt 3. Qt 4 also provides a more convenient ""programming interface for editing documents. These ""improvements are made available through a reimplementation ""of the existing text rendering engine, and the ""introduction of several new classes. ""See the relevant module overview for a detailed discussion ""of this framework. The following sections provide a brief ""overview of the main concepts behind Scribe.");
setWindowTitle(tr("Plain Text Layout"));
}
00065voidWindow::paintEvent(QPaintEvent *event)
{//! [0]QTextLayout textLayout(text, font);
qreal margin = 10;
qreal radius = qMin(width()/2.0, height()/2.0) - margin;
QFontMetrics fm(font);
qreal lineHeight = fm.height();
qreal y = 0;
textLayout.beginLayout();
while (1) {
// create a new line QTextLine line = textLayout.createLine();
if (!line.isValid())
break;
qreal x1 = qMax(0.0, pow(pow(radius,2)-pow(radius-y,2), 0.5));
qreal x2 = qMax(0.0, pow(pow(radius,2)-pow(radius-(y+lineHeight),2), 0.5));
qreal x = qMax(x1, x2) + margin;
qreal lineWidth = (width() - margin) - x;
line.setLineWidth(lineWidth);
line.setPosition(QPointF(x, margin+y));
y += line.height();
}
textLayout.endLayout();
QPainter painter;
painter.begin(this);
painter.setRenderHint(QPainter::Antialiasing);
painter.fillRect(rect(), Qt::white);
painter.setBrush(QBrush(Qt::black));
painter.setPen(QPen(Qt::black));
textLayout.draw(&painter, QPoint(0,0));
painter.setBrush(QBrush(QColor("#a6ce39")));
painter.setPen(QPen(Qt::black));
painter.drawEllipse(QRectF(-radius, margin, 2*radius, 2*radius));
painter.end();//! [0]}